DC brush motors are whisper quiet

The DCmind DC brush type motors feature a noise
level of only 35 db − about the sound of a whispered
conversation - and 20 db less than the current standard motor. The
product includes 15, 25 and 55 watt motors with a 42 mm diameter,
and 55 and 104 watt motors with a 63 mm diameter that run on 12, 24
and 48 volts. The 42 mm/48 V unit runs at 3840 RPM no load, with
110 mNm at 3,000 RPM.

The motors high quality magnets, brushes and
ball bearings and special shaping and balancing of rotor poles
combine to reduce the energy dissipated through vibration and
resonance levels, resulting in more than 80% efficiency and a
minimum service life of 5000 hours. The units are approved in
accordance with UL 10004-1, CE, and support IP56, IP67 and IP69K.
(From $60.00 ea/production qty - stock to 12 weeks.